fast day fast-darkening • fast dye · · · Info · Definitions · Characters · · fast day · · Text Common · · Latin · · Scripts 8 · · Length 2 · · Syllables Definitions · · · (noun) a day designated for fasting. Synonyms: fast day. · · Noun Definition 1 Characters · · space U+0020 a latin small letter a U+0061 d latin small letter d U+0064 f latin small letter f U+0066 s latin small letter s U+0073 t latin small letter t U+0074 y latin small letter y U+0079